A literature is rather rapidly developing which demonstrates that many of the neuropeptides previously studied for their behavioral effects and neuroanatomical distributions have demonstrable and specific effects on components of immune system function. Moreover, some immune system cells have been shown to contain neuropeptides which they presumably use for intracellular communication in some manner analogous to brain. Since neuropeptides as well as their receptors are found distributed in parts of the brain which mediate emotion, it seems exciting, and plausible to suggest that psychosomatic interactions may be mediated by this network.